Milk strainer



Feb. 18, 1936. JOHNSON 2,031,165

MILK STRAINER Filed July 21, 1934 v 2 Sheets-Sheet 1 42 l/vvgrvroe Feb. 18, 1936. Q JOHNSON 2,031,165 I MILK STRAINER 2 Sheets-Sheet 2 Filed July 21, 1934 VENTOR C/arence ALE. Johnson 5y H15 ArTOR/VEYJ Patented Feb. 18, 1936 UNITED STATES PATENT OFFICE 2,831,165 MILK STRAINER Clarence A. E. Johnson, Minneapolis, Minn.

Application July 21, 1934,'Serial No. 736,436

4 Claims.

My invention relates to liquid strainers and more particularly milk strainers.

It has been the general practice to strain milk through cloth (cotton bags) but for sanitary reasons certain municipalities have passed ordinances prohibiting the use of such bags as well as wire screens. Furthermore, cloth bags have not been entirely satisfactory, even aside from the sanitary standpoint, for the reason that the milk must be strained when warm. Butter fat in cold milk will quickly clog a cloth bag to such an extent as to materially reduce the conducting capacity thereof. Attempts have been made to use perforated metal plates in the straining of milk but it is impossible to make the holes fine enough to do eflicient work.

The object of this invention is to provide a simple and highly efficient strainer that will remove all foreign matter from milk as required by the strictest health movements, that will not clog or absorb liquid being strained, and that can be easily and quickly cleaned after usage and put in a sanitary condition.

To the above end, generally stated, the inven tion consists of the novel devices and combinations of devices hereinafter described and defined in the claims.

In the accompanying drawings, which illustrate the invention, like characters indicate like parts throughout the several views.

Referring to the drawings:

Fig. 1 is a view of the invention partly in central longitudinal section and partly in side elevation with some parts removed;

Figs. 2 and 3 are transverse sections taken on the lines 2-2 and 3-3 of Fig. 1, respectively;

Fig. 4 is a fragmentary view partly in side elevation showing the strainer removed from the easing with a tube extension applied thereto and with the strainer discs separated for the purpose of cleansing;

Fig. 5 is a fragmentary detail view in central longitudinal section of the strainer'on an enlarged scale;

Fig. 6 is a view partly in plan and partly in section taken on the line 6- -6 of Fig. 5; and

Fig. '7 is a view partly in plan and partly in section taken on the line I'l of Fig. 5.

The numeral 8 indicates an upright cylindrical casing, the upper end portion of which is expanded to increase the diameter thereof and form an annular shoulder 9. This expanded portion of the casing 8 is normally closed, at its upper end, by a cover l8 held in place by a yoke I l and a co-operating hand-screw l2. Said yoke ll straddles the cover I 8 and easing 8 and is pivoted to short trunnions l3 for swinging movement to one side of the cover I8 to permit removal thereof. The trunnions l3 are formed with a collar [4, encircling the casing 8 below the shoulder 9, and

held against lifting movement by said shoulder under the action of the hand-screw l2. Said hand-screw l2 has threaded engagement with the transverse portion of the yoke I I and its lower end impinges the cover I8 in a cap-like seat l5 5 formed with said cover. A gasket I6 is interposed between the cover I8 and the upper end of the casing 8 to form an air-tight joint therebetween. The lower end of the casing 8 is closed by a cap l'l having a depending screw-threaded 10 discharge nipple l8.

Removably mounted in the cylinder 8 is a disclike head [9 supported on the shoulder 8 and forms a partition which divides said easing into a relatively shallow milk intake compartment 28 in the top of the casing 8 and a relatively deep strainer compartment 2| below the head l9.

Secured to the head I9 is an off-center upstanding handle 22 by which said head may be lifted from the compartment 28. A gasket 23 is interposed between the head l8 and the shoulder 9 and which head is yieldingly pressed onto the gasket 23, to form an air-tight joint between the two compartments 28 and 2|, by a yoke-like spring 24. The legs of the spring 24 rest on the 25 head ill at diametrically opposite points and the cover l8 bears on the transverse portion of the spring 24 and holds the same under compression.

Formed with the casing 8, above the head I9, is an outwardly and radially projecting screwthreaded nipple 25 for a pipe, not shown, leading from a pump constructed and arranged to deliver milk into the compartment 28 under pressure. Heretofore, it has been customary to hold a strainer bag suspended in the compartment 2| from the head l9 into which milk was fed from the compartment 28 through a central hole 26 in the head l9.

The parts thus far described are of standard and well-known construction.

Referring now in detail to the invention, the

numeral 21 indicates a tube attached to the head I9, at the axis thereof, by screw-threads and held suspended in the compartment 2| at the center thereof. The lower end of the tube 21 is normally closed by a screw-plug 28 having on its lower end a flattened lug 29 by which said plug may be turned.

It is important to note that the ends of the lug 29 terminate short of the sides of the plug 28 for a purpose that will presently appear.

Formed in the tube 21 is a longitudinally extended slot 38 which extends substantially the full length of the tube 21 and through which milk, entering the tube 21 through the hole 26, is forced under pressure.

The strainer proper consists of a multiplicity of pairs of metal plates or discs 3| telescoped onto the tube 21 in the form of a stack. The uppermost disc 3| externally bears against an annular shoulder 32 on the tube 21 at a point above the upper end of the slot 30. The lowermost disc. 3| externally rests on a pair of collars 33 on the tube 21 just below the lower end of the slot 33, and which collars are held in place by a transversely divided clamping collar 34 having at its ends a pair of outturned laterally spaced lugs in which is mounted a thumb-screw 35 for use in frictionally clamping the collar 34 on the tube 21. The discs 3| of each pair bear the one upon the other at their outer marginal portions and which portions afford opposing and co-operating strainer surfaces 36. Inwardly of the strainer surfaces 33, the discs 3| of each pair are laterally offset to afford a collecting compartment 31 that is closed, except at the axial holes 3| in the respective discs 3|, through which the tube 21 extends. Obviously, the slot 30 is completely closed to the compartment 2| by the discs 3| and which slot affords a communicating passageway from the tube 21 to the collecting compartments 31.

The pressure on the milk in the tube 21 and the compartments 31 is sufficient to force the milk through the joints between the discs 3| of each pair and between opposing discs of adjacent pairs. The strainer surfaces between the discs of adjacent pairs in indicated by the numeral 38. To increase the eificiency of the opposing and co-oper ating strainer surfaces 36 and 33, said surfaces are roughened by forming therein hair-like grooves, as indicated by the numerals 39 and 40, respectively. These roughened surfaces 39 and 43 facilitate the movement of the milk over the co-operating separating surfaces. All foreign matter in the milk removed by the separating surfaces 36 will be held in the collecting compartments 31. Milk strained by the separating surfaces 36 and 33 will escape through the joints between the discs 3| of each pair and discs 3| of adjacent pairs and be precipitated into the compartment 2| where the same will escape through the nipple l3 and be conveyed therefrom through a pipe attached to said nipple. Obviously, the straining capacity of the apparatus may be varied by varying the number of pairs of discs 3| on the tube 21 and also by varying the diameter of the discs 3|.

To cleanse the apparatus the cover I is removed and the head I!) lifted from the compartment 23 with the attached tube 21 and discs 3|. With the head l9 and attached parts removed from the casing 3 the collar 34 is moved to the extreme lower end of the tube 21 to permit the discs 3| to separate during the cleansing thereof so that all foreign matter between the several discs 3| and in the compartments 31, as well as the tube 21, may be removed and the several parts of-the strainer thoroughly sterilized. The casing I and all parts attached thereto may also be easily cleaned while the head I! and parts attached .thereto are removed from the casing 8.

In case there is not sufficient room between the normal position of the collar 34 and the lower end of the tube 21 to permit proper separation of the discs 3| a tube extension 4| may be used to receive all or part of the discs 3| on the tube 21 by an axial sliding movement of said discs thereon.

One end of the tube extension 4| is telescoped onto the lug 23 which, as previously stated, is reduced in length to receive the same, as shown in Fig. 4. On theouter end of the tube extension 4| is a fixed collar 42 which prevents the accldental removal of the collars 33, 34 and the discs 3| from said tube extension.

The laterally offset portions of the discs 3| of each pair permit slight yielding action thereof so that by pressing the collar 34 on the tube 21 toward the shoulder 32, the entire stack of discs 3| may be compressed to increase the pressure between opposing discs 3| of adjacent pairs and between the outer marginal portions of the discs 3| of each pair.

It will thus be seen that the compression of the stack of discs 3| permits milk to be strained through joints between the discs of different widths or, in other words, the fineness of the straining action may be varied, at will.

Actual commercial usage of the invention has proven highly efllcient for the purpose had in view.

From what has been said, it will be understood that the strainer described is capable of modifications as to details of construction and arrangement within the scope of the invention herein disclosed and claimed. 26

What I claim is:

1. In a device of the class described, a multiplicity of pairs of plates having aligned central holes, a tube extending through said holes, means for holding the plates on the tube with the plates of each pair contacting the one with the other at their outer marginal portions to afford cooperating strainer surfaces and with the opposing plates of adjacent pairs contacting the one with the other to afford co-operating strainer surfaces, the plates of each pair inwardly of their strainer surfaces being spaced apart to afford a collecting compartment, said tube and the collecting compartments having communicating passageways, said tube having a fluid intake opening and a tube extension applicable to one end of the tube for receiving at least part of the plates on the tube to separate the same for cleansing purposes when released by said holding means.

2. In a device of the class described, a pair of 45 axially spaced concavo-convex plates the concave sides of which are in opposing relation, said plates having wide rim portions that are parallel and rest directly, the one upon the other, at least one of the opposing faces of said rim portions being roughened to afford a strainer surface.

3. In a device of the class described, a pair of parallel axially spaced concavo -convex plates supported the one pair upon the other, the concave sides of the plates of each pair being in opposing relation, the plates of each pair having wide rim portions that are parallel and rest directly, the one uponthe other, the opposing faces of the rim portions of each pair of plates being roughened to afford strainer surfaces, a tube extending axially through aligned apertures in the pair of plates, and means for holding the pairs of plates against axial movement on the tube, said 'tube having a longitudinal closure, the ends of which terminate short of the two outermost 05 plates.

4. The structure defined in claim 3 in which one of the plate holding means is adjustable to spring the plate of each pair to vary the pressure therebetween at their contacting surfaces.

CLARENCE A. E. JOHNSON. 

